cabibau



(No Model.)

H. P. CABIRA'U. GARBON FOR ELBGTRIG LAMPS. No. 542,(525. Ptented July 16, 1895.

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.Ji 2444' a?" F m 3 M M@ UNITED STATES PATENT OFFICE.,

HENRI FRANOIS CABIRAU, OF' PARIS, FRANCE.

CARBON FOR ELECTRI LAM PS.

SPECIFICATION formng part of Letters Patent No. 542,625, dat-.ed July 16, 1895.

Application filed April 11. 1895. Serial Ne. '545,296. (No model.) Patenta& in France September 18, 1894, No. 24

To all whom may concerm 4 Be it known that I, HENRI FRANOIS CABI- RAU, a citizen of France, residing at Paris, France, have invented certain new and useful Improvements in Carbons for Electric Lam ps, (for which I have obtained French Letters PatentNo. 241,477, dated September 18,1894;) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part'of this specification.

My invention has relationto a carbon pencil or stick for electric-arc lamps of the class composed of two tubular sections, one section being substantially cylindrical and inclosed by the other section, which is substantially tubular and separated therefrorn by chambers or channels for the passage of air, and it relates particularly to the Construction and arrangement of such a carbon pencil or stick.

The principal objects of my invention are, first, to provide a carbon stickor pencil for an electric-arc lamp of simple Construction and adapted to be consuned nuch more slowly than the carbon pencils now in use, and, second, to provide in electric-arc lamps a carbon stick or pencil consisting of two sections of tubular form,one section beingsubstantially cylindrical and inclosed by the other section, which is substantially tubular, in such a inanner that there is an air channel or passage formed between the two sections.

My invention consists of a carbon pencil for electric-arc lamps, constructed and arranged in substantially the manner hereinafter described and claimed. i

The nature, characteristic features, and scopo of my invention will be more fully understood from the following description, taken in connection with the accompanying drawings, forming a part hereof, in whiche Figure 1 is a View, partly in vertical section and partly in elevation, of a carbon pencil embodying the main featu res of [ny invention, illustrating a positive carbon pencil of sub- 'stantially cylindrical form united to an outer tubular section by means ot' cement, the outer section being provided with internal ribs sup` porting the interior pencil and separating the same from the internal walls of the tubular section. Fig. 2 is a horizontal section onthe line a; m of Fig. 1. Fig. 3 is a similar section taken through a negative carbon pencil, and showing the innertubularcarbou pencil provided with ribs for separating the in ner pencil from the outer tubular inclosing-section. Fig. 4 is a vertical section on the line Z Z of Fig. 5, illustrating a modified form of pencil in which the inner tubular core or pencil is integral with the outer tube and the pencil and tube separated by channeis or air-passages extending the entire length of the compound pencil. Fig. 5 is a horizontal section on `the lineg y of Fig. 4; and Fig. G is a horizontal section of a pencil, showing a modification of the pencil illustrated in Figs. 4 and 5.

Referring to the drawings, Figs. 1, 2, and 3 illustrate a`conpound pencil, in which the sections are first formed separately andi then placed together in operative position and united by means of cement or the like. Referring to the said figures, A represents a cylindrical tubular pencil of carbon orits equivalent, and B represents an outer tubular pencil of preferably carbon inclosing the inner pencilA, nested together. In the construction of the positive carbon it has been found advantageous to form on the outer tube B a :series of ribs b, which project from the interior of the tube B, while in the negative carbon the pencil A' is preferably a cylinder and is pro- Vided with the external ribs a, as shown in Fig. 3. These ribs a or b serve to separate the interior pencil A' or A from the encircling tube B' or B, so that air spaces are formed between the two sections A' and B' or A and B. The two sections A and B may be united at one or both ends by means of cement c placed in a portion ofthe space separating the two sections, substantially as' indicated in Fg. 1 of the drawings.

A modification of the foregoing arrangement is shown in Figs. 4, 5, and 6, in which the pencil consists of one section D, channeled or grooved internally the entire length of the pencil, as indicated at d. There is thus formed a single pencil D, partially hollowed, the spaces or grooves d corresponding to the spaces formed between the separable sections A and' B or A' and B' of the compound pencil, as hereinbefore explained. In Fig. 6 the interior channels d' are of different shape in cross-section from' the Channels d of Fgs. 4 and 5, but in other respects the Construction is the same. *The spaces thus formed in the carbons of either form shown permit the circulation of air so that the carbo,n, When consu med, will burn more slowly, without inpairing the brilliancy of the light.

Having thus described the nature and objects of my invention, what I claim as new,

. in presence of two witnesses.

and desire to secure by Letters Patent, is-

1. A carbon for electric are lamps, consistng of two pencils nested together, the inner pencil being provided with a central opening and rad-ial channels or air passages form-ed between the nested pencils, substantially as and for the purposes set forth.

2. A compound carbon pencil for electric are lamps, consisting of a carbon cylinder and a tube of carbon surrounding said carbon oyl- `inder and separated by ribs therefrom, substantially as and for the purposes set forth.

3. A compound carbon pencil for electric are lamps, consisting of two nested together penci'ls cemented to each other and air openings between the nested pencils, substantiaily as and for the purposes set forth.

In testinony whereof I affix my signature HENRI FRANOIS CABIRAU. VVitnesses:

E. DE WESTRAL, CLYDE SHROPSHIRE. 

